206 Miscellanies. 



with pure white lead without any addition of chalk,) present, when 

 magnified three hundred diameters, and penetrated with Canada bal- 

 sam, a delicate mosaic of elegant coralline animalcules, invisible to 

 the naked eye, but, if sufficiently magnified, more beautiful than any 

 painting that covers them. — Annals of Natural History, p. 286, No. 

 24, for December, 1839. 



32. Analysis of the Upas, (Juice of Antiaris toxicaria,) by Mul- 

 der. — A portion of the juice of the Upas tree, brought from Java, by 

 M. Blume, yielded, on analysis by Prof. Mulder, the following 

 results : 



Vegetable albumen, . - - . - 16.14 



Gum, - - 12.34 



Resin, 20.93 



Myricin, 7.02 



Antiarin, - - - - - _ - 3.56 



Sugar, --..--- 6.31 



Extractive matter, „ , - „ - 33.70 



100.00 

 Antiarin, the only active substance of this juice, is one of the most 

 deadly poisons known. Its effects, when greatly diluted, are vomit- 

 ing, diarrhoea, convulsions, and the like. It is a peculiar neutral, 

 almost uncombinable substance, retaining its properties when mingled 

 with water, &.C. — Bull. Sci. Phys. <Sf Nat. Neerlande, 1838. 



33. Advantages of iron compared with wood Steamers. 



1. The first cost of an iron vessel is from fifteen to twenty per 

 cent, less than a wood vessel. 



2. The capacity of an iron vessel is much greater than that of a wood 

 vessel of the same dimensions, in consequence of the less space occu- 

 pied by the material ; an iron vessel of four hundred and thirty tons 

 would present about the same internal surface as a vessel of five hun- 

 dred tons, built of wood. 



3. The weight of an iron vessel is not more than two-thirds of that 

 of a wood vessel of corresponding tonnage ; hence the displacement 

 of the iron vessel is much less ; therefore the diminished power of 

 her engines and comparative quantity of fuel required, makes the 

 combined displacement very much in favor of the iron steamer. 



4. An iron steamer is of much greater durability, without the repairs 

 rendered necessarj- by the common wear and tear of wood steamers. 

 It was stated before the House of Commons, that an iron vessel had 

 been worked for thirty-six years, and that an iron steamer had been 

 constantly employed for sixteen years, and at the expiration of that 



